I do think that there can be a time and a place for these devices but only if they are in the correct hands. There are too many people out there who don't know how to use these tools. I have seen rattle bottles used completely inappropriately and I hate some forms of treat training. Yes use them as positive reinforcement but, you get those that can only get their dog to come to them if they have a treat.

Point is, everything can have its place but at the same time in the wrong hands can be a complete disaster.